1. Field of the Invention
This invention relates to a peak detector for detecting the magnitude of the peak of a signal applied to an input of the detector.
2. Description of Related Art
In many data systems it is desirable to get a rapid estimate of the amplitude in order to obtain slicing levels early in a signal burst, but producing a very sensitive and fast detector means that the noise bandwidth is large and that the signal amplitude can easily be over-estimated. Thus, there is a basic incompatibility of two requirements. That is, a rapid following of the peak to monitor the maximum amplitude of the signal is desirable but a slower response is required to prevent the occurrence of noise spikes from unduly affecting the detected peak value. One application of such a peak detector is in a data slicer, particularly for teletext signals. In this application a fast estimation of the amplitude of the signal is required in order to generate a data slicing level. This estimate is normally derived from the clock run-in signal which has a limited duration and hence the peak detector needs to be able to detect the peaks relatively quickly. If, however, there are noise spikes on the signal these are likely to generate incorrect data slicing levels if the peak detector reacts too quickly to them.